Merge pull request #3855 from wonder-sk/project-refactoring-part1

Project refactoring - part I

doc/api_break.dox

@@ -250,6 +250,7 @@ should now call QgsCoordinateReferenceSystem::invalidateCache() and QgsCoordinat
   - removeLegendLayerAction() moved to QgisInterface::removeCustomActionForLayerType()
 - QgsLegendModel was removed.
 - QgsMapCanvasMap. It is an internal class used by map canvas.
+- QgsMapLayerRegistry. Its functionality has been moved to QgsProject.
 - QgsMapRenderer. It has been replaced by QgsMapRendererJob with subclasses and QgsMapSettings.
 - QgsPseudoColorShader. This shader has been broken for some time and was replaced by QgsSingleBandPseudoColorRenderer.
 - QgsRendererV2DataDefinedMenus was removed. Use QgsDataDefinedButton instead.
@@ -526,6 +527,7 @@ QgsComposerLegendItem        {#qgis_api_break_3_0_QgsComposerLegendItem}
 QgsComposerMap        {#qgis_api_break_3_0_QgsComposerMap}
 --------------
 
+- layerSet() and setLayerSet() have been replaced by layers() and setLayers() which work with list of layers instead of layer IDs
 - containsWMSLayer() has been renamed to containsWmsLayer()
 - mapRenderer() has been removed. Use mapSettings() instead.
 - All grid style and format enums were moved to QgsComposerMapGrid.
@@ -1120,6 +1122,7 @@ QgsMapLayerRegistry        {#qgis_api_break_3_0_QgsMapLayerRegistry}
 QgsMapOverviewCanvas        {#qgis_api_break_3_0_QgsMapOverviewCanvas}
 --------------------
 
+- layerSet() and setLayerSet() have been replaced by layers() and setLayers() which work with list of layers instead of layer IDs
 - destinationSrsChanged() was renamed to destinationCrsChanged()
 
 
@@ -1173,6 +1176,7 @@ The whole class has been refactored to stop using WKB and to use QgsAbstractGeom
 QgsMapSettings        {#qgis_api_break_3_0_QgsMapSettings}
 --------------
 
+- layers() and setLayers() now work with list of layers instead of layer IDs
 - layerTransform() now returns a QgsCoordinateTransform object, not a pointer. An invalid QgsCoordinateTransform will
 be returned instead of a null pointer if no transformation is required.
 - destinationCrs() now returns a copy instead of a reference to the CRS. This has no effect on PyQGIS code, but c++

python/core/composer/qgscomposermap.sip

@@ -136,9 +136,9 @@ class QgsComposerMap : QgsComposerItem
     void setKeepLayerSet( bool enabled );
 
     /** Getter for stored layer set that is used if mKeepLayerSet is true */
-    QStringList layerSet() const;
+    QList<QgsMapLayer*> layers() const;
     /** Setter for stored layer set that is used if mKeepLayerSet is true */
-    void setLayerSet( const QStringList& layerSet );
+    void setLayers( const QList<QgsMapLayer*> layers );
     /** Stores the current layer set of the qgis mapcanvas in mLayerSet*/
     void storeCurrentLayerSet();